At 80 psi I would not bother with a PRV, and without the PRV, ( or a check valve in the supply line which is rare), an expansion tank has absolutely...
The water passage down to the "tub" port and then back up to the shower opening goes past the operating mechanism so it you tried to drill it larger...
In my expierence repairing frozen pipes over the decades, unless you temper the heat around the pipes, they will freeze. Bundled pipes in foam at 10...
You do not need a PRV at the meter, but if the building is actually 150 below the meter, then you will have about 150 psi at the building which means...
C is the vent for the tub, and the pipe extending horizontally is the trap arm before the p-trap is glued on. We always install the trap "after" the...